From bd07b59079d22f75add9889eec6e4f84ce0b2678 Mon Sep 17 00:00:00 2001
From: Martin Willi <martin@strongswan.org>
Date: Thu, 17 Jul 2008 11:45:58 +0000
Subject: [PATCH] avoid heap allocation in bus->signal for performance reasons

---
 src/charon/bus/bus.c | 81 +++++++++++++++++++++++++++++++++-------------------
 src/charon/bus/bus.h |  4 ---
 2 files changed, 51 insertions(+), 34 deletions(-)

diff --git a/src/charon/bus/bus.c b/src/charon/bus/bus.c
index 5f813e7..1c57fcc 100644
--- a/src/charon/bus/bus.c
+++ b/src/charon/bus/bus.c
@@ -253,46 +253,67 @@ static void set_sa(private_bus_t *this, ike_sa_t *ike_sa)
 	pthread_setspecific(this->thread_sa, ike_sa);
 }
 
-	
 /**
- * Implementation of bus_t.vsignal.
+ * data associated to a signal, passed to callback
  */
-static void vsignal(private_bus_t *this, signal_t signal, level_t level,
-					char* format, va_list args)
-{
-	iterator_t *iterator;
-	entry_t *entry;
+typedef struct {
+	/** associated IKE_SA */
 	ike_sa_t *ike_sa;
+	/** invoking thread */
 	long thread;
-	
-	this->mutex->lock(this->mutex);
-	ike_sa = pthread_getspecific(this->thread_sa);
-	thread = get_thread_number(this);
-	
-	iterator = this->listeners->create_iterator(this->listeners, TRUE);
-	while (iterator->iterate(iterator, (void**)&entry))
+	/** signal type */
+	signal_t signal;
+	/** signal level */
+	level_t level;
+	/** format string */
+	char *format;
+	/** argument list */
+	va_list args;
+} signal_data_t;
+
+/**
+ * listener invocation as a list remove callback
+ */
+static bool signal_cb(entry_t *entry, signal_data_t *data)
+{
+	if (!entry->listener->signal(entry->listener, data->signal, data->level,
+						data->thread, data->ike_sa, data->format, data->args))
 	{
-		va_list args_copy;
-		va_copy(args_copy, args);
-		if (!entry->listener->signal(entry->listener, signal, level, thread, 
-									 ike_sa, format, args_copy))
+		if (entry->blocker)
 		{
-			iterator->remove(iterator);
-			if (entry->blocker)
-			{
-				entry->blocker = FALSE;
-				entry->condvar->signal(entry->condvar);
-			}
-			else
-			{
-				entry_destroy(entry);
-			}
+			entry->blocker = FALSE;
+			entry->condvar->signal(entry->condvar);
+		}
+		else
+		{
+			entry_destroy(entry);
 		}
-		va_end(args_copy);
+		return TRUE;
 	}
-	iterator->destroy(iterator);
+	return FALSE;
+}
+
+/**
+ * Implementation of bus_t.vsignal.
+ */
+static void vsignal(private_bus_t *this, signal_t signal, level_t level,
+					char* format, va_list args)
+{
+	signal_data_t data;
+	
+	data.ike_sa = pthread_getspecific(this->thread_sa);
+	data.thread = get_thread_number(this);
+	data.signal = signal;
+	data.level = level;
+	data.format = format;
+	va_copy(data.args, args);
 	
+	this->mutex->lock(this->mutex);
+	/* we use the remove() method to invoke all listeners with small overhead */
+	this->listeners->remove(this->listeners, &data, (void*)signal_cb);
 	this->mutex->unlock(this->mutex);
+	
+	va_end(data.args);
 }
 
 /**
diff --git a/src/charon/bus/bus.h b/src/charon/bus/bus.h
index 678bf37..6ceac4c 100644
--- a/src/charon/bus/bus.h
+++ b/src/charon/bus/bus.h
@@ -320,10 +320,6 @@ struct bus_t {
 	 *
 	 * Same as bus_t.signal(), but uses va_list argument list.
 	 *
-	 * @todo Improve performace of vsignal implementation. This method is
-	 * called extensively and therefore shouldn't allocate heap memory or
-	 * do other expensive tasks!
-	 *
 	 * @param singal	kind of the signal (up, down, rekeyed, ...)
 	 * @param level		verbosity level of the signal
 	 * @param format	printf() style format string
-- 
2.7.4